The electronic cigarette substituted for traditional tobacco has been used widely due to the strengthening of anti-smoking publicity and the improvement of health consciousness. The existing electronic cigarette consists of a cigarette rod and a cigarette holder, the cigarette rod is provided with a battery, the cigarette holder is equipped with an atomizer, the atomizer is electrically connected to the cigarette rod. The cigarette holder is provided with a oil cup for holding tobacco juice, the tobacco juice slowly flows into the atomizer when user begins to smoke with the cigarette holder. The atomization silk of the atomizer imbibes the tobacco juice, the control circuit of the cigarette rod senses the current, the tobacco juice is atomized by the heating device of the atomization silk and the smog is formed to be inhalant.
When the atomization silk of the atomizer gives off heat and atomizes the tobacco juice, the heat will be transmitted to the external of the electronic cigarette. The existing heat-insulating protections of the external of the electronic cigarette is less, generally having a protective sleeve or a protective sleeve and a layer of sticker, the protective sleeve is hot and may be burn the user if he has smoked for a long time.